Tomato pinworms have recently been found infesting tomatoes in a greenhouse in Delaware. According to Jerry Ghidiu, an entomologist with Rutgers University, once pinworms become established they can move quickly through the house and threaten the entire crop. He stated that tomato pinworm is difficult to control and it is best to catch it early; multiple applications of insecticides will be needed for control. First instars are foliar feeders and mine into the leaf. Older larvae may fold the leaf over itself, or stick leaves together. In severe infestations all leaves are infested and the crop may have a burnt appearance. Larvae can then move into the fruit, making control much more difficult. Larvae will leave small pinholes at entry points. Pinworm can complete its life cycle in 28 days and there may be more than 7-8 generations per year. Adults are small gray moths and once adults are seen, infestations are severe. Pheromone traps can be used to detect and monitor the moths.
Entomologists in the region recommended Pylon as the best control labeled for greenhouse tomato use to control this pest. They also noted Entrust as another material to consider especially for organic production; however, it carries the following restriction: “Do not apply to seedling fruiting vegetables (which includes tomatoes) and okra grown for transplant within a greenhouse, shade house, or field plot.” As with all materials, you need to read the label for rates and restrictions before applying. Please refer to the Commercial Vegetable Production Recommendations for additional products to use in a rotation.